{"id":62892,"date":"2025-01-31T17:53:35","date_gmt":"2025-01-31T17:53:35","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=62892"},"modified":"2025-01-31T17:57:29","modified_gmt":"2025-01-31T17:57:29","slug":"satellite-estimates-of-heavy-rain-over-hawaii","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/62892","title":{"rendered":"Satellite estimates of Heavy Rain over Hawaii"},"content":{"rendered":"\n
\"\"<\/a>
MIMIC estimates of Total Precipitable Water, hourly from 0000 UTC 28 January through 1500 UTC 31 January 2025 (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n

The potent cyclone (surface analysis<\/a>, an airmass RGB animation from the College of Dupage website<\/a> is below) that caused severe weather over Hawaii (blog post<\/a>) is also drenching the islands with considerable rains. The animation of MIMIC Total Precipitable Water, above, shows the storm drawing tropical moisture northward from the Intertropical Convergence Zone. The airmass RGB, below, also shows that connection to the tropics, with the green area in the RGB that is moving northward over Hawaii. <\/p>\n\n\n\n

\"\"<\/a>
GOES-18 airmass RGB, 2310 UTC 30 January 2025 – 1530 UTC 31 January 2025 (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n

How have various estimates of precipitation quantified the rains that have fallen? Hourly CMORPH-2<\/a> Rain Estimates captured at this RealEarth<\/a> site (enter ‘CMORPH’ into the Search box; this website<\/a> has data through 31 December 2024), below, capture the progress of the heavy rain band across the islands, mostly west to east, but with a couple of seemingly backward steps.<\/p>\n\n\n\n

\"\"<\/a>
CMORPH-2 esimates of hourly rainfall, 0400-1300 UTC on 31 January 2025 (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n

In contrast, GOES-18 GREMLIN estimates of MRMS radar reflectivity, shown below with GOES-18 mid-level water vapor infrared imagery, shows steady eastward progress to the heavy rainband. A band of lighter precipitation persists over Kauai however. The animation below suggests the backward steps in the CMORPH hourly precipitation shown above are artifacts that bear investigation. A discussion on how GREMLIN rain estimates are used over Pago Pago in the south Pacific is available here<\/a>.<\/p>\n\n\n\n

\"\"<\/a>
GOES-18 mid-level water vapor imagery (band 9, 6.95, left) and GOES-18 GREMLIN estimates of MRMS radar (right), every 10 minutes from 2230 UTC 30 January through 1500 UTC 31 January 2025 (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n

There is a direct broadcast antenna at Honolulu Community College (link<\/a>) and microwave data from that site can be used to derive instantaneous rain rates (via MIRS algorithms<\/a>). The animation below shows three snapshots between 0715 and 1215 UTC.<\/p>\n\n\n\n

\"\"<\/a>
Rain rate estimates from MetopB AMSU (0715 UTC), NOAA-21 ATMS (1149 UTC) and Suomi NPP ATMS (1215 UTC) (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n

How do the instantaneous rain rates compare with GREMLIN MRMS estimates? Three comparisons are shown below. The figures are qualitatively similar.<\/p>\n\n\n\n

\"\"<\/a>
GREMLIN estimates of MRMS rainfall, 0720 UTC, left and MIRS Rain Rate from MetopB AMSU\/MHS, 0715 UTC on 31 January 2025 (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n
\"\"<\/a>
GREMLIN estimates of MRMS rainfall, 1150 UTC, left and MIRS Rain Rate from NOAA-21 ATMS, 1149 UTC on 31 January 2025 (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n
\"\"<\/a>
GREMLIN estimates of MRMS rainfall, 1220 UTC, left and MIRS Rain Rate from Suomi-NPP ATMS, 1215 UTC on 31 January 2025 (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n

When evaluating heavy rains, there are many products available to a forecaster. Use them all to increase confidence in the diagnostics.<\/p>\n","protected":false},"excerpt":{"rendered":"

The potent cyclone (surface analysis, an airmass RGB animation from the College of Dupage website is below) that caused severe weather over Hawaii (blog post) is also drenching the islands with considerable rains. The animation of MIMIC Total Precipitable Water, above, shows the storm drawing tropical moisture northward from the Intertropical Convergence Zone. The airmass […]<\/p>\n","protected":false},"author":19,"featured_media":62909,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[114,58,93,131,49],"tags":[],"class_list":["post-62892","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-goes-18","category-metop","category-mirs","category-noaa-21","category-suomi_npp"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/62892","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/users\/19"}],"replies":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/comments?post=62892"}],"version-history":[{"count":10,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/62892\/revisions"}],"predecessor-version":[{"id":62916,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/62892\/revisions\/62916"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/62909"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=62892"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=62892"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=62892"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}